1. Field of the Invention
This invention relates to a surface treating agent for treating the surface of glass, glass lenses, mirrors, plastics, plastic lenses, metals, ceramics, porcelain, and pottery for forming anti-fouling substances which are tack-free, anti-dust-sticking, water repellent, and oil repellent.
2. Background Art
It is known to impart anti-fouling and water repellent properties to optical lenses such as eyeglass lenses and camera lenses by forming cured coatings of silicone or fluorocarbon polymers as the outermost surface layer. The treating agent used to this end is proposed in U.S. Pat. No. 4,678,688, for example, as comprising a trifunctional polysilazane such as C.sub.8 F.sub.17 C.sub.2 H.sub.4 Si(NH).sub.3/2 or C.sub.4 F.sub.9 C.sub.2 H.sub.4 Si(NH).sub.3/2 or polysiloxazane. When an article is treated with such a trifunctional silicon compound alone, its surface is covered solely with a polymer having a three-dimensional structure. This coating is soft or tacky and thus has the drawback that dust will deposit and stick thereto and fingerprints are left after the coating is touched with fingers.
JP-A 233535/1990 discloses a glass surface treating agent comprising a perfluoro group-bearing silane, an organopolysiloxane, an acid and an organic solvent. This agent is not fully satisfactory in water repellent and anti-fouling properties.